The present invention relates to apparatus and method for positioning connection equipment on a drilling rig. Such connection equipment may be, but not limited to a power tong, spinner or iron roughneck.
In the drilling of a borehole in the formation of an oil or gas well, a drill bit is arranged on the end of a drill string and is rotated to bore the borehole. The drill string comprises a string of tubulars known as drill pipe sections. A drill pipe section comprises an upper and lower end. The upper end is provided with an enlarged section having a female thread, known as the box end; and the lower end is provided with an upstand and a male thread, known as the pin end. Sections of drill pipe are connected into stands of two or three sections. This may be carried out away from well center using a mouse-hole or rat-hole located in a floor of a drilling rig platform. Once a stand of drill pipe has been constructed, the stand is moved from the mouse-hole or rat-hole and stored in a rack. The stands are then moved from the rack to well center and connected to a string of drill pipe in the well.
To accomplish the connection between drill pipe, whether in the form of a section, stand or string, was carried out with two tools: a spinner; and a torque wrench. For example, a pin of an upper section of drill pipe is lowered into the box of a lower section retained in a mouse-hole. The spinner spins the upper section of drill pipe threading the pin end into the box. The spinner is then removed and the torque wrench is offered up to the upper section of drill pipe. The torque wrench comprises a power tong to rotate the upper section of drill pipe and a back-up tong to inhibit reaction rotation of the lower section of drill pipe retained in the mousehole. The back-up tong is used during torquing and may also be used during spinning. The tong is activated to rotate the drill pipe section or stand and torque the connection to a required torque, typically less than one rotation. The torque wrench and back-up tong are then removed from the drill pipe. An apparatus known as an iron roughneck, combines a spinner with a tong and back-up tong and may also comprise a form of stabbing guide to ensure alignment of the pin and box.
In certain types of joint, upon torquing, a face of the upstand known as the “shoulder” and a face of the box meet and there is a sharp rise in torque required to turn the upper drill pipe relative to the lower. This type of joint normally requires less than forty-five degrees of turn for the torquing step after the spinning step. However, some connections do not have shoulders and are continuous threads, such as Hydril Wedge Thread type connections. Such connection generally require more than a quarter turn of torquing.
During work over of a well, a string of pipe is lowered into the well in much the same way as for the drill string. However, the string is sometimes referred to as a tool string rather than a drill string.
Other tubulars are used in the construction and maintenance of an oil or gas well, such as casing. Casing is usually screwed in single sections at the well center and lowered into the well. The casing is then hung from the top of the well and may be cemented in place. Other tubulars known as liner is screwed together and lowered into the well. The liner is hung from the bottom of a section of casing and may be cemented in place. A power tong or iron roughneck may be used to facilitate connection of these tubulars. Such tubulars often have threaded connections and require the use of iron roughnecks, power tongs and spinners to perfect the connections.
Downhole tools may also be connected into any of a: drill string; tool string; casing; or liner. These downhole tools may be connected with screwed threads and thus require spinning and torquing.
The above described method for spinning and torquing can be applied to any of the tubulars with screw threaded connection as described above.
“Iron roughnecks” combine a torque wrench and a spinning wrench to connect and disconnect tubulars, e.g. drilling components, such as drill pipe, in running a string of tubulars into or out of a well. Prior art tong systems and iron roughnecks are shown. e.g., in U.S. Pat. Nos. 4,023,449; 4,348,920; 4,765,401; 6,318,214; 6,776,070; 7,249,639; and 7,313,986 all of which are incorporated herein by reference in their entirety.
Various prior art iron roughnecks have a spinning wrench and a torque wrench mounted together on a carriage. For making or breaking threaded connections between two tubulars, for example joints of drill pipe, certain iron roughnecks have a torque wrench with two jaw levels. An upper jaw of the torque wrench is used to clamp onto a portion of an upper tubular, and a lower jaw clamps onto a portion of a lower tubular, for example upper and lower threadedly connected pieces of drill pipe. After clamping onto the connected tubulars, the upper and lower jaws are turned relative to each other to break a connection between the upper and lower tubulars. A spinning wrench, mounted on the carriage above the torque wrench, engages the upper tubular and spins it until it is disconnected from the lower tubular.
Certain prior art iron roughneck systems include a carriage for rolling on the surface of the rig floor along a predetermined path. In certain prior art systems a spinner and torque wrench are mounted for upward and downward movement relative to a carriage, for proper engagement with tubulars, and for tilting movement between a position in which their axis extends directly vertically for engagement with a vertical well pipe and a position in which the axis of the spinner and torque wrench is disposed at a slight angle to true vertical to engage and act against a pipe in an inclined mousehole. In certain prior art systems, a spinner is movable vertically with respect to a torque wrench.
Certain iron roughnecks are mounted on an extendable and retractable support structure for movement to and from a wellbore center without interfering with or blocking performance of other operations relative to the well and rotating or driving apparatuses.
U.S. Pat. No. 7,249,639, co-owned with the present invention, discloses an apparatus for moving an Iron Roughneck into position to allow making-up or breaking-out of threaded joints in a drill string. The apparatus may also be used to move other drilling equipment into position on the centerline of the well or at mouseholes. A self-balanced, dual synchronized parallelogram arm is utilized to accomplish the movement of the devices. Hydraulic or pneumatic cylinders are used for extension and retraction of the arm rather than to support the tool. The arm may hold the tool in any position without cylinder assistance. The linkage in the synchronized parallelogram may be accomplished by gears, links, slots, or rollers. In certain aspects, an apparatus is disclosed for moving drilling equipment having: a column attached to a drill floor; a column guide attached to the column; at least one parallelogram arm attached to the column guide at a first connection point, the at least one parallelogram arm comprising a tension link, a lower support arm, an upper support arm, a compression link, and a load transfer joint; a drilling apparatus attached to the parallelogram arm at a second connection point; and a cylinder attached to the column guide for raising and/or lowering the column guide along the column.
U.S. Patent 7,313,986, co owned with the present invention, discloses a system with a torque wrench and a spinning wrench on a carriage which is movably connected for up/down vertical movement to a column and which can also translate horizontally on a rig floor for movement toward and awmay from a drill pipe of a drill string in a well. Support arms are pivotably connected at one end to a base of the carriage and at their other ends to a support. Optionally, only one support arm is used or two arms in parallel are used. A connector is removably emplaceable in a socket to mount the system on a rig. In one particular aspect the dual arms move the spinner/wrench combination outwardly 24″ (60.96cm) from the column which results in a 6.5″ (16.51cm) rise vertically. The wrenches are movable by a power mechanism toward and away from the column 14 by moving the support arms. The spinning wrench is movable up and down on the carriage toward and away from the torque wrench. A control console for the communicates by wire or wirelessly with the system components and can be located remotely.
US 2005/004788Belik and US 2005/024169Lechtenberger disclose a positioning system for an Iron Roughneck, the positioning system comprising column guide arranged on a column spaced from well center and mousehole. A self-balanced, dual synchronized parallelogram arm is suspended from the column guide and is retractable and extendable therefrom. Hydraulic or pneumatic cylinders are used to extend and retract the arm. Synchronization is accomplished with gears, links, slots or rollers. The hydraulic or pneumatic piston is used to extend and retract the arm from a vertical storage position to various distances therefrom. A plurality of mechanical stops may be used to control the extension of the arm from the column for different distances therefrom, such as to the well center and mousehole. The mechanical stop is arranged between a member of the arm and the column guide. A sensor of a PLC is used in controlling the height of the column guide on the column.
The inventor has noted that distances between the well-center and the column on which the Iron Roughneck positioning apparatus is mounted is rarely the same as the distance between the mouse-hole and the column on which the Iron Roughneck positioning apparatus is mounted. Operators rely on eye to position the Iron Roughneck at well-center or at the mouse-hole. The inventor has noted a need for an apparatus and a method of improving speed and accuracy of aligning the connection equipment, such as an Iron Roughneck, power tong, spinner etc. with a tubular in a mouse-hole, rat hole, at well center and at other locations of use. The inventor has noted that the connection equipment is used at one location for a large number of operations. For example, an iron roughneck will be used at the mouse-hole to construct dozens of stands of drill pipe and then will be used at well center to connect dozens of stands of tubulars to the drill string. He has also noted that connection equipment will be used continuously at well center connecting sections of casing. The inventor has noted that connection apparatus is rarely swung randomly between well-center and mouse-hole, or between a further mouse-hole, rat-hole, tool connection area etc.